From 1969 to 1977 117 patients with malignant kidney tumours were treated. Because of the slow tumour growth, the absence of early symptoms, the uncharacteristic clinical picture and a case history of long duration most of the tumours were in a very advanced stage. Only 69 patients (58.9%) were qualified for tumour-nephrectomy. The five years survival rate was 49%. An improvement of these unsatisfactory results can be achieved only if the diagnosis is made as early as possible and if adequate surgical treatment is ensured. As far as possible excretory urography should be indicated as a real screening method. Angiographic analysis and surgical treatment by transperitoneal radical tumour-nephrectomy are the methods of choice.